首页
登录
职称英语
It may be debated whether individual neurons are "tuned" to react to
It may be debated whether individual neurons are "tuned" to react to
游客
2024-01-11
27
管理
问题
It may be debated whether individual neurons are "tuned" to react to only a
single tastant such as salt or sugar-and therefore signal only one taste
quality-or whether the activity in a given neuron contributes to the neural
Line representation of more than one taste. Studies show that both peripheral and
(5) central gustatory neurons typically respond to more than one kind of stimulus,
and although each neuron is attuned most acutely to one tastant, it usually also
generates a reaction to others with dissimilar taste qualities. How then can the
brain represent various taste qualities if each neuron is receptive to many
different-tasting stimuli?
(10) Electrophysiological studies of gustatory sensory neurons, first performed
by Pfaffmann, demonstrated that peripheral neurons are not specifically
responsive to stimuli representing a single taste quality (which might be
symbolized by the pattern of activity across gustatory neurons because the
activity of any one cell was ambiguous) but instead record a spectrum of tastes.
(15) But in the 1970s and 1980s several scientists began to accumulate data indicating
that individual neurons are tuned maximally for one taste, and they interpreted
this as evidence that activity in a particular type of cell represented a given taste
quality—an idea they called the labeled-line hypothesis. According to this idea,
activity in neurons that experience the strongest reaction to sugar would signal
(20) "sweetness," activity in those that are most sensitive to acids would signal
"sourness", and so forth.
Smith later proved that the same cells that previous researchers had
interpreted as labeled lines actually defined the similarities and differences in
the patterns of activity across taste neurons, suggesting that the same neurons
(25) were responsible for taste-quality representation, whether they were viewed as
labeled lines or as critical parts of an across-neuron pattern. These investigators
further established that the neural distinction among stimuli of different
qualities depended on the simultaneous activation of different cell types, much
as with the function of color vision, but unlike auditory perception. These and
(30) other considerations have led us to favor the idea that the patterns of activity
are key to coding taste information.
Scientists now know that things that taste similarly evoke similar patterns
of activity across groups of taste neurons. Furthermore, we can compare these
patterns and use multivariate statistical analysis to plot the similarities in the
(35) patterns elicited by various tastants. Taste researchers have generated such
comparisons for gustatory stimuli from the neural responses of hamsters and
rats and these correspond very closely to similar plots generated in behavioral
experiments, from which we may infer which stimuli taste alike and which taste
different to animals. Such data show that the across-neuron patterns contain
(40) sufficient information for taste discrimination and this may be a reasonable
explanation for neural coding in taste, though researchers continue to debate
whether individual neuron types play a more significant role in taste coding than
they do in color vision. Scientists question whether taste is an analytic sense, in
which each quality is separate, or a synthetic sense like color vision, where
(45) combinations of colors produce a unique quality. [br] Which of the following laboratory results, if found, would be LEAST consistent with the author’s explanation of the neurophysiology of taste?
选项
A、A group of taste neurons is found which only responds to sweet taste when stimulated by sweet foods.
B、A brain-wave analysis of a rat genetically engineered to lack a sense of sweet tastes is nevertheless found to have a sense of sour tastes.
C、Most tastes are found to have strikingly different neurological effects on humans they do upon animals.
D、A brain-wave analysis of a hamster demonstrates a similar pattern of activity in a given neurological area for both sour and sweet stimuli.
E、A group of taste neurons is found which provides insufficient information for taste discrimination.
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3354005.html
相关试题推荐
WhetheryouarehikingthroughthemagnificentredwoodsofNorthernCaliforni
Scientistsnowhavesomesurprisinganswersaboutwhetherbrainpower______aswe
______themanagerwillcomeornotdoesn’tmattermuch.A、WhetherB、ThatC、IfD、
Theworriedmotheraskedallthe______inthestreetwhethertheyhadseenher
IamnotsurewhetherNewYorkis_______biggestcityin________worldornot.A、a;
()thereisfreshair,thereisoxygen.A、WhereverB、WheneverC、UnlessD、Whether
Theworriedmotheraskedallthe______inthestreetwhethertheyhadseenher
______itwilldousharmorgoodremainstobeseen.A、IfB、WhetherC、WhyD、HowB
Itseemslikeeverydaythere’ssomenewresearchaboutwhetherourfavorite
Itseemslikeeverydaythere’ssomenewresearchaboutwhetherourfavorite
随机试题
Cricket,althoughlovedbymillionsofpeople,isnotoneoftheeasiestspo
某旅游企业为了获得更大的收益,决定进军家居行业,该企业采取的战略是()。A.相
设x为一个总体且E(x)=k,D(x)=1,X1,X2,…,xn为来自总体的简单
以下水准仪中哪一种型号的精度最高()。A.DS10 B.DS3 C.DS0
根据《普通高中美术课程标准(实验)》,不属于高中美术课程性质的是()。A.理
根据现行《合同法》规定,合同是()。 A平等主体的自然人、法人、其他
某游戏比赛决赛采用BO5赛制,即五局三胜制,根据以往经验,单局比赛R队胜F队的概
期货公司变更住所,应当提交的申请材料包括(??)。A.变更住所申请书 B.
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
各级政府及其所属部门根据法律、行政法规等规定,为支持某项特定基础设施建设和社会公
最新回复
(
0
)